Application of optical deformation analysis system on wedge splitting test and its inverse analysis

An alternative approach of fracture tests evaluation based on optical measurements of displacements is investigated in this paper. The non-linear hinge model based inverse analysis outgoing from the optically measured crack mouth opening displacements is introduced for the wedge splitting test. Results of the inverse analysis are compared with traditional inverse analysis based on clip gauge data.

Then the optically measured crack profile and crack tip position are compared with predictions done by the non-linear hinge model and a finite element analysis. It is shown that the inverse analysis based on the optically measured data can provide material parameters of the fictitious crack model matching favorably those obtained by classical inverse analysis based on the clip gauge data.

Further advantages of using of the optical deformation analysis lie in identification of such effects as aggregates bridging and crack branching. These effects would remain hidden if the crack profile is simulated by a model based on the fictitious crack model.